[Probabilistic risk assessment of dietary exposure to lead among Chongqing residents].

OBJECTIVE: To investigate lead contamination in commercial foods in Chongqing City, and to assess the health risk of dietary lead exposure of residents in Chongqing City. METHODS: Lead concentration data was obtained from the food safety risk monitoring system, which included a total of 2347 lead-containing food samples in 11 categories in Chongqing from 2016 to 2020. Consumption data was derived from the China Health and Nutrition Survey Project in Chongqing in 2018(3 day, 24 h dietary recall survey). The dietary exposure to lead of residents in Chongqing was calculated by the Monte Carlo simulation method and the margin of exposure(MOE) method was used to evaluate the health risk of the population. RESULTS: The average content of lead in 2347 food samples from 11 categories ranged from 0.0328 to 0.0363 mg/kg, with an overall detection rate of 58.5%. For people aged between 3-6, 7-17, 18-59, and ≥ 60 years, the mean dietary lead intakes in Chongqing were 0.935-1.070, 0.600-0.684, 0.367-0.416, 0.369-0.419 µg/(kg·BW·d), respectively; and the high levels of dietary lead exposure(P95) were 1.642-1.852, 1.147-1.299, 0.651-0.729, 0.659-0.740 µg/(kg·BW·d), respectively. MOE values for lead were less than 1 for age groups 3-6 and 7-17 years. Mean MOE values for lead were greater than 1 for ages 18 to 59 and ≥ 60. Cereals and their products, vegetables and their products, and meat and meat products were the main sources of dietary lead exposure, accounting for more than 85% of the total dietary lead exposure. CONCLUSION: There are potential health risks of lead for residents in Chongqing.

The association between physical activity and body fat percentage with adjustment for body mass index among middle-aged adults: China health and nutrition survey in 2015.

BACKGROUND: The inverse association between physical activity and body fat percentage (%) varies among different populations. We aim to examine whether the significant association between them was uniform across the subpopulations after taking into account body mass index (BMI). METHODS: Our study relied on data from China Health and Nutrition Surveys in 2015, including 5763 participants aged 40-64 years from 15 regions. Physical activity was calculated as metabolic equivalent task hours per day (MET·h/d). Body fat% was measured by bioelectrical impedance analysis. Body mass index < 24 kg/m2 was defined as normal weight and BMI ≥ 24 kg/m2 was overweight/obese. The effects of physical activity on body fat% were estimated using the Kruskal-Wallis test among sex, age, BMI groups, education, income, region and urbanization. Quantile regression analyses were utilized to describe the relationship between physical activity and body fat% distribution. RESULTS: Older adults, overweight/obese, higher education, higher income, residents of central China and those living in areas of higher urbanization had the lower physical activity. Participants who engaged in the highest level of physical activity had 2.0 and 1.5% lower body fat% than the lowest level of physical activity group (23.4, 34.8%) for men and women, respectively. There were 10.4 and 8.8% of normal weight males and females called normal weight obese. Overall, 1 h extra 4.5 MET•h/d was significantly associated with 0.079 and 0.110% less total body fat% at the 75th and 90th percentiles in normal weight males, with 0.071% less at the 25th percentiles in overweight/obese males, with 0.046-0.098% less at the 25th to 90th percentiles in normal weight females, and with 0.035-0.037% less from the 50th to 90th percentiles in overweight/obese females. The inverse association between physical activity and total body fat% was stronger in normal weight obese participants than other subgroups. CONCLUSIONS: In middle-aged Chinese adults, the inverse association between physical activity and body fat% was only in particular subpopulations rather than the entire population. We should pay much attention to normal weight obese and give a suitable physical activity guideline taking into account people with different body fat%.

Bidirectional mediation of evening energy proportion and chronotype on their associations with blood lipid levels in a Chinese population.

The bidirectional relationship between chronotype and meal energy distribution, and the effect of their relationship on blood lipid level has not been investigated. This study aims to test and compare the bidirectional mediating effects of chronotype and meal energy distribution on blood lipid levels. Data of 9376 adult participants from 2018 wave of the China Health and Nutrition Survey (CHNS) were analysed. Two mediation models were tested and compared: one with Evening energy proportion (Evening EI%) as mediator of the association between adjusted mid-sleep time on free days (MSFa) and blood lipid levels and the other with MSFa as mediator of the association of Evening EI% with blood lipid levels. The mediating effect of Evening EI% on the association between MSFa and TC, LDL-C and non-HDL-C were significant (p < .001, p = .001, and p = .002, respectively). The mediating effect of MSFa on the association between Evening EI% and TC, LDL-C and non-HDL-C were significant (p = .006, p = .035, and p < .001 respectively). Evening EI% had a larger standardized mediation effect compared to MSFa. The bidirectional mediation effect suggests a reinforcement mechanism, in which later chronotype and higher Evening EI% reciprocally influence their negative impact on elevated blood lipid levels, leading to higher risk of cardiovascular diseases in the general population.

Longitudinal Association between Physical Activity, Blood Lipids, and Risk of Dyslipidemia among Chinese Adults: Findings from the China Health and Nutrition Surveys in 2009 and 2015.

Physical activity is needed in today's highly sedentary society. Research into Chinese trends with respect to the longitudinal association between changes in physical activity (PA) and dyslipidemia (DL) is limited. The present study assessed PA and PA-related changes associated with the level of serum lipids, and the risk of dyslipidemia stratified by gender, via a population-based longitudinal observational study among adults (>18 years old) residing in nine provinces in China. Data of 3380 adult participants, gleaned from two surveys in 2009 and 2015 used by the China Health and Nutrition Survey (CHNS), were analyzed. Three-level random intercept growth models were used to calculate the associations between total physical activity (TPA), the four activity subtypes, and changes in the level of blood lipids. Three-level logistic regression models were utilized to assess the association between TPA and the risk of DL. The highest level of TPA was observed to correlate with the lowest prevalence of DL. Compared with the lowest level of TPA, the highest level of TPA increases the concentration of HDL-C (ß = 0.050, 95% CI = 0.005, 0.096) in males, and also reduces the risk in males of having low HDL-C by 31% (OR = 0.69, 95% CI = 0.52, 0.91). Occupational PA was positively associated with higher HDL-C levels in both genders (males: ß = 0.004, 95% CI = 0.002, 0.007; females: ß = 0.002, 95% CI = 0.000, 0.004), and leisure-time physical activity (LTPA) was negatively associated with TG levels in males. Increasing TPA benefited HDL-C levels in males, irrespective of the level of basic TPA of individuals. Physical activity (especially occupational PA) was superior in positively influencing HDL-C in males, but not in females. Leisure-time physical activity needs to be increased substantially in order to increase TPA to levels that would be beneficial to blood lipid levels and DL, irrespective of baseline TPA levels.

The Mediation and Moderation Effect Association among Physical Activity, Body-Fat Percentage, Blood Pressure, and Serum Lipids among Chinese Adults: Findings from the China Health and Nutrition Surveys in 2015.

Physical activity (PA) is of benefit and particularly important for cardiovascular disease risk factors as being sedentary becomes a lifestyle habit. Research into Chinese complex association among physical activity, body-fat percentage (BF%), blood pressure, and serum lipids is limited. The present study is based on an observational study among adults (>18 years old) residing in fifteen provinces in China. Data of 10,148 adult participants in the 2015 China Health and Nutrition Survey (CHNS) were analyzed. The simple mediation effect models with covariates were utilized to assess the association among PA and blood pressure or serum lipids, and BF% was played as a mediator. The serial multiple-mediator models with covariates were constructed to the further analysis of the relationship between PA and blood pressure, and BF% was the mediator 1 and blood lipids were the mediator 2. Based on the above hypothesis, the moderated mediation models with covariates were used to analyze the association among PA, BF%, and blood pressure; in addition, BF% was used as the mediator and blood lipids played as the moderator. In the simple mediation models, the model with a dependent variable was high-density lipoprotein cholesterol (HDL-C) or low-density lipoprotein cholesterol (LDL-C); BF% was played as the partly mediation effect and the proportion of contribution was 0.23 and 0.25, respectively. In the serial multiple-mediator models, blood lipids, as the second mediator, played the mediation effect; however, the effect was smaller than the BF%. In the moderated mediation model, blood lipids had the moderation effect as the moderator variable. HDL-C played a moderating role in the latter pathway of the "PA→BF%→SBP/DBP" mediation model, and LDL-C/TC played a moderating role in the direct effect of the "PA→BF%→DBP". In conclusion, BF% played a mediating role in the relationship between PA and blood pressure. HDL-C, LDL-C, and TC were more likely to act as moderating variables in the mediation model "PA→BF%→SBP/DBP". PA could directly and indirectly benefit to control the CVD risk factors simultaneously.

A foodborne outbreak linked to Bacillus cereus at two middle schools in a rural area of Chongqing, China, 2021.

Bacillus cereus (B. cereus) is a common cause of foodborne illness. An outbreak of acute gastrointestinal illness occurred at two middle schools in a rural region of Chongqing, China, in 2021. This study aimed to elucidate the outbreak's characteristics, identify risk factors, and determine the source of contamination. A retrospective cohort study and an environmental investigation were conducted. Vomit samples, anal swabs, and food samples were collected and tested by RT-PCR for 18 species of bacteria and viruses, including B. cereus. Positive samples of B. cereus underwent biochemical experiments and bacterial quantification. A total of 198 cases were reported in this outbreak, with an attack rate of 24.63%. The main symptoms were vomiting (100%), bellyache (83.33%), and dizziness (62.63%). The retrospective cohort study showed a significant association between the outbreak and rice noodles provided by a nearby food manufacturer (RR = 39.63, p < 0.001). B. cereus was detected in 20 vomit samples, three anal swabs, and seven rice noodles samples, with a count exceeding 103 CFU/g. These findings strongly suggested that the outbreak was linked to B. cereus-contaminated rice noodles. Enhancing food safety surveillance and promoting health measures among schools and food manufacturers in rural areas is crucial to prevent similar incidents in the future in Chongqing, China.

Longitudinal association between physical activity and blood pressure, risk of hypertension among Chinese adults: China Health and Nutrition Survey 1991-2015.

OBJECTIVES: To examine the effects of physical activity (PA) in adults with or without prehypertension at baseline on systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension risk by gender. METHODS: A total of 5986 men and 6525 women (≥18 years old) without hypertension-related disease at baseline who attended surveys from China Health and Nutrition Survey (1991-2015) at least twice were selected. In terms of the nested data structure, three-level random intercept growth model and three-level logistic regression were used to estimate the relationship between the PA and SBP/DBP or hypertension risk. RESULTS: The incidence of hypertension increased from 10.86% in 1991 to 20.34% in 2015, and the median of PA dropped from 408 MET·h/week in 1991 to 104 MET·h/week in 2015. After adjusting confounders, PA in the third and fourth quartiles decreased SBP (by 0.98 and 0.96 mm Hg, p < 0.05) and DBP (by 0.30 and 0.38 mm Hg, p < 0.05), and it reduced the odds of hypertension by 12 and 15% (p < 0.05), compared with PA in the lowest quartile. For normotensive women in the third quartile of PA and prehypertensive women in the fourth quartile of PA, the risk of hypertension was reduced 15 and 22%, compared with women in the lowest quartile of PA. CONCLUSIONS: Physical activity should be improved to the relatively high level to be effective in controlling blood pressure. Normotensive women had an association between physical activity and SBP, DBP, and the risk of hypertension.

Trends in Leisure-Time Physical Activity Among Chinese Adults - China, 2000-2015.

What is already known about this topic? The monitoring report on nutrition and health status of Chinese residents from 2010 to 2013 reported that the participation rate of leisure-time physical activity (LTPA) was 13.8% among those 6 years and older. What is added by this report? Among 18 years old and older, the age-standardized LTPA prevalence increased from 7.13% in 2000 to 11.79% in 2011 before dropping to 7.33% in 2015. What are the implications for public health practice? As levels of LTPA participation are low, further research is necessary to develop and test valid interventions to encourage people to take part in more LTPA especially for residents in rural areas and with low-income.

Source specific PM2.5 associated with heart rate variability in the elderly with coronary heart disease: A community-based panel study.

There is increasingly concern that PM2.5 constituents play a significant role in PM2.5-related cardiovascular outcomes. However, little is known about the associations between specific constituents of PM2.5 and risk for cardiovascular health. To evaluate the exposure to specific chemicals of PM2.5 from various sources and their cardiac effects, a longitudinal investigation was conducted with four repeated measurements of elderly participants' HRV and PM2.5 species in urban Beijing. Multiple chemicals in PM2.5 (metals, ions and PAHs) were characterized for PM2.5 source apportionment and personalized exposure assessment. Five sources were finally identified with specific chemicals as the indicators: oil combustion (1.1%, V & PAHs), secondary particle (11.3%, SO42- & NO3-), vehicle emission (1.2%, Pd), construction dust (28.7%, Mg & Ca), and coal combustion (57.7%, Se & As). As observed, each IQR increase in exposure to oil combustion (V), vehicle emission (Pd), and coal combustion (Se) significantly decreased rMSSD by 13.1% (95% CI: -25.3%, -1.0%), 27.4% (95% CI: -42.9%, -7.6%) and 24.7% (95% CI: -39.2%, -6.9%), respectively, while those of PM2.5 mass with decreases of rMSSD by 11.1% (95% CI: -19.6%, -1.9%) at lag 0. Elevated exposures to specific sources/constituents of PM2.5 disrupt cardiac autonomic function in elderly and have more adverse effects than PM2.5 mass. In the stratified analysis, medication and gender modify the associations of specific chemicals from variable sources with HRV. The findings of this study provide evidence on the roles of influential constituents of ambient air PM2.5 and their sources in terms of their adverse cardiovascular health effects.

Methods for measuring horizontal equity in health resource allocation: a comparative study.

ᅟ: There are many existing methodologies on measuring health equity, while seldom has method aiming at health resource allocation. We collected 6 method of measuring equity in health resource allocation. This paper presents key contents of methods on measuring horizontal equity in health service allocation, yet each method has its advantages and disadvantages as well as range of application, which may help researchers or government to make wise decision when choosing appropriate method for measuring equity. Through comparative analysis, we concluded that socioeconomic factors were considered in concentration index; although the Lorenz curve and Gini-coefficient are widely used, which exist uncertainty and incompleteness; overall inequality can be decomposed by Theil index, which is of significance for the planning of urban and rural areas; preferences on a certain class can be set artificially by Atkinson index; it is easy for Chi-square to analyze aided with statistical software; specific regional differences can be calculated by index of dissimilarity. CLASSIFICATION CODES: I1.